Control mechanism for hydrostatic pump

Abstract

A control mechanism for controlling a reversible pump that selectively supplies fluid to two different motors forming separate functions includes a control lever pivoted about a fixed axis and having said pump connected thereto. A control console is located adjacent the control lever and cooperates therewith to define a plurality of distinct operating positions on opposite sides of a neutral position for said control lever. The control lever and control console also have releasable interlock means defining the neutral position for the control lever and the pump.

What is claimed is: 
     
       1. In a vehicle having a reversible pump supplying hydraulic fluid to at least two motors controlling separate functions with selector means between said motors and said pump for selecting one function, said pump having a control arm movable in opposite directions from a neutral position, a control unit including a control lever pivoted on a fixed axis on said vehicle and having said arm connected thereto, releasable interlock means between said control lever and said vehicle defining a neutral position for said arm, a control console adjacent said control lever, said control console and control lever having a first position defining means defining a plurality of positions on one side of said neutral position for operating one selected motor at a plurality of levels of operation and second position defining means on an opposite side of said neutral position for operating the other selected motor at a plurality of levels of operation. 
     
     
       2. A vehicle as defined in claim 1, in which said releasable interlock means includes a quadrant carried by said control lever and having an opening and a spring biased pin biased toward said quadrant and received into said opening when said control lever is in a neutral position. 
     
     
       3. A vehicle as defined in claim 2, in which said control lever includes a first portion pivoted on said fixed axis and a second portion carried by said first portion with biasing means between said portions and in which said second portion has projection means forming part of said position defining means. 
     
     
       4. A vehicle as defined in claim 3, in which each position defining means includes a plurality of spaced apertures on each side of said neutral position. 
     
     
       5. A control unit for a reversible pump for controlling a function with said pump having a control arm movable in opposite directions from a neutral position to operate said function, said control unit including a control lever pivoted about a fixed axis on a frame and having said arm connected thereto at a location spaced from said fixed axis, a safety quadrant secured to said control lever and movable therewith, said safety quadrant having a single opening movable along a path with said control lever, a safety latch supported on said frame in said path and biasing means biasing said safety latch toward said quadrant, and position defining means defining a plurality of distinct positions for said control lever on said frame. 
     
     
       6. A control unit as defined in claim 5, in which said position defining means includes an elongated member adjacent said path and having a plurality of spaced apertures along said path and said control lever has a position defining element biased toward said member and aligned with said apertures. 
     
     
       7. A control unit as defined in claim 6, in which said control lever includes a first portion pivoted on said fixed axis and a second portion carried by said first portion with biasing means between said portions, said position defining element being supported on said second portion and biased toward said apertures. 
     
     
       8. A control unit as defined in claim 7, in which said elongated member has an elongated slot with said control lever movable along said slot, said elongated member having first and second sets of equally spaced apertures on opposite sides of said slot, said position defining element including first and second pins respectively secured to said second portion of said control lever and respectively aligned with said first and second sets of apertures. 
     
     
       9. A control unit as defined in claim 7, in which said first portion includes a rod extending through said elongated member and said second portion includes a sleeve telescoped over said rod with the biasing means between said rod and sleeve, said position defining element being secured to said sleeve between said elongated member and said fixed axis and biased toward said elongated member. 
     
     
       10. A control unit as defined in claim 5, in which said safety latch includes a pin biased to a first position wherein a free end of the pin is located in said opening, said free end having a second position engaging a surface of said safety quadrant in any position of said control lever other than said neutral position so that said pin is received into said opening when said control lever is moved to said neutral position. 
     
     
       11. A control unit as defined in claim 5, in which said pump is adapted to supply two motors respectively controlling first and second functions with selector means between said motors and pump for selecting one motor, and in which movement of the control lever in one direction from neutral controls one function, and movement of the control lever in an opposite direction from neutral controls the other function. 
     
     
       12. A control unit pivoted about a fixed axis on said vehicle, said vehicle including a control panel having an elongated slot through which said control lever projects, said control lever including a first portion pivoted on said fixed axis and a second portion telescoped on said first portion, said portions having overlapping segments located in said slot and biasing means between said portions, said control panel having a set of spaced apertures located in a plane extending parallel to said slot, said second portion having projection means aligned with said apertures so that said biasing means biases said projection means into an aperture when aligned therewith, and interlock means between said control panel and said control lever defining said neutral position. 
     
     
       13. A control unit as defined in claim 12, in which said apertures are located on one side of said slot and said control panel has a second set of apertures located on an opposite side of said slot, the apertures in the respective sets being transversely aligned and said projection means includes first and second pins respectively aligned with the respective sets of spaced apertures. 
     
     
       14. A control unit as defined in claim 12, in which said interlock means includes a safety quadrant fixed to said first portion and having a single opening therein, said control panel having a safety pin biased toward said quadrant and aligned with said opening to be received into said opening when said control lever is in a neutral position.